ES2425982T3 - Conveyor with curved trajectory - Google Patents

Abstract

Conveyor for transporting articles through a helical path around a central axis (2a) in a vertical direction, comprising a frame (1) that holds a continuous conveyor belt (8) that moves along the helical path and is driven by motor means in a transport direction, said conveyor belt (8) that includes carrier plates (9) that are connected to each other, each with an upper transport face (10), said frame that includes at least one guide (14 ) to guide the carrier plates (9) along the helical path, where at least several carrier plates (9) comprise at least one first guide roller (11) rotatable on a rotation axis (12) with a component that is extends in a direction perpendicular to the transport face (10), said first guide roller (11) having at least a first guide roller surface (17) that is in contact with a first surface of g guide (15) of the guide (14) in a first contact location (19) so that the first guide roller (11) is radially supported by the guide (14), and a second guide roller surface (18 ) which is in contact with a second guide surface (16) in the guide (14) in a second contact location (20), whose first and second contact places (19,20) are spaced apart from each other, where the normal of the first guide roller surface (17) in the first contact location (19) deviates from the normal of the second guide roller surface (18) in the second contact location (20) so that the first guide roller ( 11) is also supported upwards by the guide (14), characterized in that said carrier plate (9) has at least one second guide roller (11a) spaced from the first guide roller (11) in the radial direction of the central axis (2a), whose second guide roller (11a) is adapted to be supported ado and rolled along a second guide (14a) in the frame.

Description

Conveyor with curved trajectory.

[0001] The present invention relates to a conveyor for shipping items according to the preamble of the claim

one.

[0002] Such a conveyor is known from US 5,429,227. EP 1 009 692 B1 also discloses a conveyor provided with carrier plates comprising guide rollers that are guided by a guide with a vertical guide surface. The known arrangement of the guide and the guide roller has resulted in a reduction of frictional forces during the movement of a carrier plate along the helical path.

[0003] It is an objective of the present invention to provide an improved conveyor that operates at an even higher transmission efficiency.

[0004] To achieve this objective, the conveyor according to the invention is characterized by the features of claim 1.

[0005] Due to these characteristics the guide roller of the carrier plate is supported by the guide in two different directions; in practice being a direction parallel to the axis of rotation as well as perpendicular to it. As the guide roller is supported in both directions, the movement of the guide roller with respect to the guide can be effected by rolling the guide roller along the guide with little or no sliding. This results in lower friction between the carrier plate and the guide during the movement of the carrier plate along the guide, resulting in high transmission efficiency.

[0006] The conveyor according to the invention is convenient for sending items in a vertical direction.

[0007] The axis of rotation can extend substantially perpendicular to the transport face. The advantage of this orientation is that the guide roller can be placed close to the transport face resulting in a compact construction height of a carrier plate.

[0008] The normal to the first guide roller surface at the first contact location may be substantially perpendicular to the axis of rotation. This has the benefit of low friction between the first guide roller surface and the first guide surface in the first contact location since this feature produces a rolling movement only of the first guide roller surface on the first surface of guide.

[0009] In a preferred embodiment the first contact location is located near the second contact location in the radial direction of the axis of rotation, because in that configuration the difference in the speed of rotation of the guide roller in the first and second place of contact is small or even zero. Therefore, the sliding of the guide roller with respect to the guide in the second contact location is minimized, resulting in improved efficiency.

[0010] Preferably, the second guide and guide roller surfaces are adapted so that the second contact location substantially forms a point contact. This has the advantage that the sliding in the second contact location due to a variable distance to the axis of rotation is minimized.

[0011] The first guide roller surface can be formed by a cylindrical shaped guide roller part, while the first guide surface can extend parallel to the axis of rotation in a plane perpendicular to the transport direction, so both forming a line contact between the guide roller and the guide in the first contact location. A line contact has the advantage of a stable guide support to the guide roller in the direction of the rotation axis and provides low rolling resistance.

[0012] The second guide surface may be adjacent to the first guide surface and extend obliquely downwardly viewed from the central axis to the axis of rotation. The advantage of this configuration is that a cylindrical guide can be applied without the risk of friction of a roller bearing along the guide.

[0013] The guide roller can have a cylindrical shape and the guide can have a concave shaped cross section as seen in the transport direction, where the guide is oriented so that the opening of the concave shaped cross section receives the guide roller in the radial direction of the rotation axis. A lower wall of the channel opening comprises the second guide surface, the bottom of the channel comprises the first guide surface and an upper wall of the channel opposite the lower wall comprises a third guide surface for guiding the roller of

guide along the guide if the carrier plate rises upward when the conveyor is in operation. The advantage of this configuration is that it is relatively simple to produce and provides a guide to guide a roller guide down and up the carrier plate.

[0014] Alternatively, the second guide roller surface may be formed by at least one disposed flange. coaxially with the guide roller which is adapted so that the second guide roller surface is adjacent to the first guide roller surface and extending obliquely upwardly seen in the radial direction of the axis of rotation. Such a guide roller with flange can be manufactured relatively easily.

[0015] Preferably, the guide roller has a diameter shape with a circumferential groove defined by a wall upper comprising the second guide roller surface, a bottom wall that extends coaxially with the axis of rotation, this bottom wall comprises the first guide roller surface, and a bottom wall opposite the upper wall comprising a third guide roller surface for guiding the guide roller along the guide if the Carrier plate rises up when the conveyor is running. The advantage of a guide roller in Diameter shape is that the guide not only holds the guide roller in the upward direction and radial direction thereof, but also down when the carrier plate rises upwards.

[0016] According to the invention, the carrier plate has at least a second guide roller spaced from the guide roller. in a radial direction of the central axis, that second guide roller is adapted to be supported by and rolled along a second guide in the frame. It is advantageous when the carrier plate is supported in more than one support location by guide rollers to eliminate any sliding contact between the carrier plate and the guides.

[0017] Preferably, the second guide roller has identical dimensions to the first guide roller, since this minimizes manufacturing costs

[0018] The carrier plate can be symmetrical mirror, where a plane perpendicular to the upper transport face and parallel to the direction of transport forms the line of symmetry. A symmetrical configuration facilitates the manufacturing process.

[0019] The invention will be hereafter further explained in connection with the drawings showing forms of embodiment of the conveyor according to the invention by way of example. Fig. 1 is a general and very schematic side view of an embodiment of a conveyor according to the invention. Fig. 2 is a plan view of the conveyor frame of figure 1. Fig. 3 is a larger-scale plan view of the carrier plates of a small part of the conveyor belt of the conveyor of figures 1 and 2 in the helical path. Fig. 4 is a larger-scale cross-sectional view along line IV-IV in Fig. 3 perpendicular to the upper face of transport of the carrier plate. Fig. 5 is an enlarged view of a part of Figure 4. Fig. 6 is a view corresponding to that of Fig. 5 showing an alternative embodiment of the guide roller and the guide.

[0020] Fig. 1 shows a conveyor adapted to transport articles, through a helical path in vertical direction In practice such conveyors are known as spiral conveyors or conveyors of curl These conveyors are capable of transporting items in a continuous flow in a direction of transport. This product flow can be used for vertical transport or as a buffer in a section of processing Areas of use are for example the food processing industry, distribution centers, the Graphics industry and the like.

[0021] The conveyor as shown comprises a frame 1, in this case including a central column 2 with a central axis 2a, feet 3 and a helical guide ramp 4 that extends around column 2 and fixed thereto. By Of course several types of other frame structures are also conceivable. A final pulley 5.6 is provided in the upper and lower extremities of the guide ramp 4, and between these extremities of the helical guide ramp 4 is extends a return ramp 7 of the frame 1. In this case a continuous conveyor belt 8, which is supported by the Frame 1, is guided through another path in the shipping part and the return part. However, embodiments they are conceivable in which the part sent is guided back to the lower side of the guide ramp 4. The tape Conveyor is driven by drive means (not shown) in the transport direction.

[0022] In the case as shown, the helical guide ramp 4 includes four windings, but this number may increase or decrease depending on the particular case. Due to the invention it is possible to drive the conveyor belt 8 continuous through a large number of windings without drive problems and at high efficiency. In the way of embodiment shown a drive motor can engage the final pulley at the end of the conveyor path, which is the final pulley 5 or 6, and if desired it is also possible to use auxiliary motors in other positions on the track

transport. A linear drive for the continuous conveyor belt 8 is also conceivable. The conveyor can be attached to other conveyors in the upper and lower end pulleys 5, 6.

[0023] Fig. 3 shows a plan view of the carrier plates of a small part of the conveyor belt of the conveyor. Fig. 4 shows a cross-sectional view in a plane perpendicular to the direction of the shipment (along the line IV-IV in Fig. 3). With reference to these figures, the continuous conveyor belt 8 comprises a plurality of movable carrier plates 9 coupled to each other, either directly or through a continuous connecting element, such as a side arc chain. In the embodiment, each carrier plate 9 has an upper flat transport face 10. The carrier plates 9 are attached to each other so closely in the transport path that the articles can be supported by several adjacent carrier plates 9.

[0024] Fig. 4 shows an embodiment of a carrier plate 9 having two guide rollers: a guide roller 11 and a second guide roller 11a, which are spaced apart from each other in the radial direction of the central axis 2a (X address). Both guide rollers 11,11a are rotatable about an axis of rotation 12,12a which extends in the Y direction. The Y direction is here defined as extending perpendicular to the upper transport face, which is near the vertical in the practical, depending on the angle of inclination of the helical path. The orientation of the rotation axes 12,12a of the guide rollers 11,11a is not restricted to the Y direction. Rotation axes 12,12a which extend obliquely with respect to the Y direction are also conceivable. For example, it is possible that both guide rollers 11,11a comprise axes of rotation 12,12a having angles opposite each other in the plane perpendicular to the direction of transport, for example, an orientation with "V" shaped axes when viewed in the direction of transport.

[0025] The guide rollers 11,11a are articulated in corresponding rotating shafts 13,13a, preferably by means of a bearing to obtain a homogeneous operation of the guide rollers 11,11a.

[0026] In the embodiment shown in Fig. 4 the guide rollers 12 concur with a guide 14 and a second guide 14a, respectively, which are fixed to the frame 1. In this case the central column 2 of the conveyor 1 is locate to the right (X direction) of the carrier plate 9 in Fig. 4. This means that the main radial forces under normal operation of the conveyor are exerted on the guide roller 11 and the guide 14 in Fig. 4, and that the guide 14 is capable of holding the guide roller 11 in an opposite radial direction of the central axis 2a. In Fig. 4 the carrier plate 9 including the guide rollers 11,11a are symmetrical by reflection in a plane perpendicular to the upper transport face 10 and parallel to the transport direction. In the embodiment as shown, this plane intersects the center of the carrier plate 9 in the axial direction thereof. It is also possible that the second guide roller 11a is designed and mounted on the carrier plate differently with respect to the guide roller 11. The guides 14 and 14a as shown in Fig. 4 comprise a groove shape along the helical trajectory, whose grooves confront and guide the guide rollers 11,11a. While the second guide roller 11a has a larger distance from the central axis 2a than the guide roller 11, the second guide 14a has a larger diameter than the guide 14 seen along the central axis 2a.

[0027] Fig. 5 shows an enlarged view of a part of the embodiment as shown in Fig. 4. The guide 14 comprises a first guide surface 15 and a second guide surface 16. The guide roller 11 comprises a first guide roller surface 17 and a second guide roller surface 18. When the conveyor is operating the first guide roller surface 17 and the first guide surface 15 are in contact with each other in a first contact location 19 , and the second guide roller surface 18 and the second guide surface 16 are in contact with each other in a second contact location 20.

[0028] The first contact location 19 forms a line contact since the guide roller 11 is cylindrical and the first guide surface 15 extends parallel to the axis of rotation 12 in a plane perpendicular to the direction of transport in this way of realization. It should be noted that a line contact is a mathematical term and in practice a line contact will only be approximate.

[0029] According to the invention, the normal of the first guide roller surface 17 in the first contact location 19 and the normal of the second guide roller surface 18 in the second contact location deviate from each other, which can be seen in Fig. 5. Due to this feature, the guide roller 11 can be supported upwards (Y direction) and radially (X direction) by the guide 14. The second contact location 20 is preferably a contact point, which is located very close to the first contact location 19 to minimize sliding between the guide roller 11 and the guide 14 due to differences in the rotation speed of the guide roller 11 in the first and second contact places 19, 20. This means that the second guide surface 16 is preferably adjacent to the first guide surface 15 and extends downwardly as seen from the first guide surface 15 in the direction ion of the rotation axis 12 in the case of a cylindrical guide roller 11 to create a point contact at the second contact location 20 in the case of a cylindrical roller 11. It should be noted that a point contact is a mathematical term and in practice a point contact will only be approximate.

[0030] In the embodiment of Figure 5 the guide 14 has a concave shaped cross section. The opening of the channel is directed radially to the axis of rotation 12 and extends along the helical path. The concave shaped guide 14 comprises the second guide surface 16 as a bottom wall of the opening, the first guide surface 15 as a bottom of the channel and a third guide surface 21 as a top wall of the channel. The third guide surface 21 is opposite the second guide surface 16 and serves to guide the guide roller 11 along the guide 14 if the carrier plate 9 is raised upward (Y direction) with respect to the frame.

[0031] In the alternative embodiment of the guide roller 11 and the guide 14 as shown in Fig. 6 the guide roller 11 has a diameter shape. This guide roller 11 can be made of a cylindrical roller circumferentially covered by a diabolic shaped covering element that is made of plastic such as nylon, for example. In this embodiment, a part of the guide 14 which fits in the circumferential groove of the guide roller in the form of a diaphragm 11 has a cross-section in the form of a rectangle. Preferably the angles of this part of the guide in front of the groove have a rounded shape to avoid a too high local contact pressure, as shown in Fig. 6.

[0032] The guide 14 comprises the first guide surface 15 and the second guide surface 16. In this embodiment, the second guide surface 16 is facing up to hold the guide roller in the form of a diameter 11 upwards in the second guide roller surface 18. When the conveyor is operative the first guide roller surface 17 and the first guide surface 15 are in contact with each other in the first contact location 19. The first contact location 19 forms a line contact since the first guide roller surface 17 forms a cylindrical portion and the first guide surface 15 extends parallel to the axis of rotation 12 in a plane perpendicular to the direction of transport. The second guide roller surface 18 and the second guide surface 16 are in contact with each other in a second contact location 20.

[0033] The second guide roller surface 18 is adjacent to the first guide roller surface 17 and extends obliquely upwardly seen from the axis of rotation 12. The opening of the circumferential groove of the diameter is defined by the second surface of guide roller 18 as an upper wall, the first guide roller surface 17 as a bottom wall extending parallel to the axis of rotation 12, and a third guide roller surface 22 as a bottom wall opposite the upper wall The third guide roller surface 22 serves to guide the guide roller along the guide if the carrier plate rises upward when the conveyor is in operation.

[0034] From the foregoing it will be clear that the invention provides a conveyor that is capable of achieving low resistance between the carrier plates and the guide during operation. Due to the deviation from the normal of the first and second guide roller surfaces in the first and second contact places, respectively, the conveyor provides high transmission efficiency.

[0035] The invention is not limited to the embodiments described above, which may vary in various forms within the scope of the claims. For example, the carrier plate may comprise a first guide roller with a substantially vertical axis of rotation and another guide roller with a horizontal axis of rotation perpendicular to the transport direction to hold the carrier plate upwards only. The carrier plate and the guide can then comprise a well known element that prevents the carrier plate from moving upwards. With respect to the alternate embodiment with the guide roller in the form of a diameter, the second guide surface of the guide roller can be formed, for example, by only a flange that is arranged coaxially with the cylindrical guide roller instead of a diabolo shape that includes two coaxial flanges. The third contact surface can then be formed by a sliding contact in case the carrier plate rises upwards.

Claims (13)

1. Conveyor for transporting articles through a helical path around a central axis (2a) in a vertical direction, comprising a frame (1) holding a continuous conveyor belt (8) that moves along the path helical and driven by motor means in a transport direction, said conveyor belt

(8)

 which includes carrier plates (9) that are connected to each other, each with an upper transport face (10), said frame that includes at least one guide (14) to guide the carrier plates (9) along the path helical, where at least several carrier plates (9) comprise at least one first guide roller (11) rotating on a rotation axis (12) with a component extending in a direction perpendicular to the transport face (10), said first guide roller (11) having at least a first guide roller surface (17) that is in contact with a first guide surface (15) of the guide (14) in a first contact location (19) of way that the first guide roller

(eleven)

 it is radially supported by the guide (14), and a second guide roller surface (18) that is in contact with a second guide surface (16) in the guide (14) in a second contact location (20), whose first and second contact places (19,20) are spaced apart from each other, where the normal of the first guide roller surface (17) in the first contact location (19) deviates from the normal of the second surface of guide roller (18) in the second contact location (20) so that the first guide roller (11) is also supported upwardly by the guide (14), characterized in that said carrier plate (9) it has at least a second guide roller (11a) distanced from the first guide roller (11) in the radial direction of the central axis (2a), whose second guide roller (11a) is adapted to be supported and rolled at length of a second guide (14a) in the frame.

2.

 Conveyor according to claim 1, wherein the first contact location (19) is located near the second contact location (20) in the radial direction of the rotation axis (12) of the first guide roller (11).

3.

Conveyor according to claim 1 or 2, wherein at least the second guide and guide roller surfaces (17,18) are adapted so that the second contact location (20) substantially forms a point contact.

Four.

Conveyor according to one of the preceding claims, wherein the first guide roller surface (17) is formed by a cylindrical shaped guide roller part, while the first guide surface (15) extends parallel to the axis of rotation (12) in a plane perpendicular to the transport direction, therefore forming a line contact between the first guide roller (11) and the guide (14).

5.

Conveyor according to claim 4, wherein the second guide surface (16) is adjacent to the first guide surface (15) extending obliquely downwardly seen from the central axis (2a) to the axis of rotation (12) of the first roller guide (11).

6.

 Conveyor according to one of the preceding claims, wherein the first guide roller (11) has a cylindrical shape and the guide (14) has a concave shaped cross section as seen in the transport direction, where the guide (14) it is oriented such that the opening of the concave shaped cross section receives the first guide roller (11) in the radial direction of the rotation axis (12), where a lower wall of the channel opening comprises said second guide surface (16), the bottom of the channel comprises the first guide surface (15) and an upper wall of the channel opposite the lower wall comprises a third guide surface (21) to guide the first guide roller (11) along of the guide (14) if the carrier plate (9) rises upward in a direction parallel to the axis of rotation (12) when the conveyor is operational.

7.

Conveyor according to one of claims 1-4, wherein the second guide roller surface (18) is formed by at least one flange arranged coaxially with the first guide roller (11) whose flange is adapted so that the second surface of Guide roller (18) is adjacent to the first guide roller surface (17) and extends obliquely upwardly seen in the radial direction of the rotation axis (12).

8.

Conveyor according to claim 7, wherein the first guide roller (11) has a diabolic shape with a circumferential groove defined by an upper wall comprising the second guide roller surface (18), a cylindrical bottom wall that extends coaxially with the axis of rotation (12) whose bottom wall comprises the first guide roller surface (17), and a lower wall opposite the upper wall comprising a third guide roller surface (22) to guide the first guide roller (11) along the guide (14) if the carrier plate (9) rises upward in a direction parallel to the axis of rotation (12) when the conveyor is in operation.

9.

Conveyor according to one of the preceding claims, wherein the second guide roller (11a) has dimensions identical to those of the first guide roller (11).

10.

 Conveyor according to one of the preceding claims, wherein the carrier plate (9) is symmetrical by reflection, where a plane perpendicular to the upper transport face (10) and parallel to the transport direction forms the line of

symmetry. 11. Conveyor according to one of the preceding claims, wherein both guide rollers (11,11a) are rotatable about axes of rotation (12,12a) that extend perpendicular to the transport face (10). 5 12. Conveyor according to one of the preceding claims, wherein the axis of rotation (12) of the first guide roller (11) extends substantially perpendicular to the transport face (10). 13. Conveyor according to one of the preceding claims, wherein the normal of the first guide roller surface 10 (17) in the first contact location (19) is substantially perpendicular to the axis of rotation (12) of the first guide roller ( eleven).